1. Field of the Invention
The present invention relates to a water valve, more specifically to a non-return structure of water valve.
2. Description of the Prior Art
A conventional non-return structure of water valve, as shown in patent TW 509300, is integrally formed rubber having an end with a circular inlet and an opposite end with an obliquely reduced outlet. Two semicircular anti-leaking rings are disposed around the circular inlet, and a stepped portion above the rings forms annular grooves. In addition, an enhancing element is provided. Thereby, water is prevented from flowing reversely.
However, water from a reverse direction still strikes against the circumference of the outlet, so the circumference of the outlet may be deformed so that the outlet is opened. Thus, water may flow reversely.